Abstract: An electronic circuit for use with an exhaustible power source and load such as a light bulb, a radio or motor, includes a microchip with an input that transmits a signal to the microchip when the load is activated or deactivated. The input does not form a serial link between the power source and the load. The power switch, by on/off switching, controls energy flow from the power source to the load. The electronic circuit has an automatic delayed shut-off function for the load and, a find-in-the-dark indicator and a power source level indicator which are active when the load is not energized and the power source is not being charged. The input to the microchip acts as an activation/deactivation user interface. The microchip allows the user to select specific functions based on the time duration of activation signals, the time duration between activation signals and the number of activation signals at the input.

Abstract: A preferred embodiment of the electrical power system of the present invention includes a power conditioning unit which is configured to receive the DC electrical output signal to deliver an AC output signal to a grid-connected load. Preferably, the power conditioning unit includes a controller which is configured to monitor the AC output signal so that the power conditioning unit may cease delivering the AC output signal when a characteristic of the AC output signal satisfies an established criterion.

Abstract: A power supply includes a turn on circuit which coordinates turn on of all paralleled power supplies supplying power to an electronic system such as a computer system. Upon detecting that its input voltage is sufficient to turn on, the power supply waits for a delay period long enough to ensure readiness of any of the paralleled power supplies and then determines that it can start independently. Upon detecting bus voltage sufficient to ensure that another power supply has turned on, the power supply determines that another power supply has turned on. If either condition is determined, the power supply turns on and begins supplying power to the computer system. As a result, the first power supply to turn on will be detected by the other power supplies, and the other power supplies will turn on immediately thereafter.